16" Durafan Select Speed Shutter Fan 3 Speed, 120 Volt, 16.5"x16.5" Rough Opening 1570/1400/1000 RPM, 3000/2100/1300 CFM Totally assembled with built-in speed switch with 9' cord attached. Corrosion resistant aluminum shutter with tie bar. Safety chrome grill on intake side meets OSHA standards.